NPARC (Named Pipe ARChive) is an NCR utility that transfers data between two Teradata systems. It is basically ARC using named pipes instead of tape, making data transfers much faster. The "donor" system runs an ARC DUMP into the pipes and the "receiver" system runs an ARC COPY with the pipes as its input. The bynets of both systems are connected via LAN cable through your node's LAN ports.
It is a professional services engagement to have it done, but I believe you can also purchase the product for your own use if you pay NCR enough. That was a while ago, NCR's stance may have changed on selling it since then. We've used NPARC when migrating to new hardware and I will say it beats dumping to and restoring from tape handily in speed and ease of use.